Collector assemblies are known in the art for connecting to construction machines, such as cranes or bulldozers, for moving and collecting debris. One such collector assembly is disclosed in U.S. Pat. No. 7,429,158, published on Sep. 30, 2008 to David L. McFarland. The collector assembly includes a center bucket and a pair of extensions that are slideably connected to opposing sides of the center bucket for expanding an operational width of the center bucket. Although such conventional collector assemblies are useful for moving debris after it has fallen to a ground, an issue is that they are not suitable for collecting debris during construction and demolition operations that take place on elevated work surfaces, such as during refinishing or demolition of a bridge. Accordingly, there are often safety and public access concerns during such operations because a large region beneath and around the elevated work surface has to be kept clear from the public. Accordingly, there remains a need for improvements to collector assemblies.